Update acct existence check in EVM.SELFDESTRUCT_gas

trailofbits · Sep 1, 2020 · 23f782d · 23f782d
1 parent fa4d888
commit 23f782d
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diff --git a/manticore/platforms/evm.py b/manticore/platforms/evm.py
@@ -2277,7 +2277,7 @@ def SELFDESTRUCT_gas(self, recipient):
         CreateBySelfdestructGas = 25000
         SelfdestructRefundGas = 24000
         fee = 0
-        if recipient not in self.world and self.world.get_balance(self.address) != 0:
+        if not self.world.account_exists(recipient) and self.world.get_balance(self.address) != 0:
             fee += CreateBySelfdestructGas
 
         if self.address not in self.world._deleted_accounts:

diff --git a/tests/ethereum/test_general.py b/tests/ethereum/test_general.py
@@ -1913,6 +1913,55 @@ def test_call_gas(self):
                 GCALLSTATIC + GCALLVALUE + GCALLNEW - GCALLSTIPEND
             )
 
+    def test_selfdestruct_gas(self):
+        GSDSTATIC = 26003  # 21000 + 3 (push op) + 5000 static cost for selfdestruct
+        GNEWACCOUNT = 25000
+        RSELFDESTRUCT = 24000
+
+        with disposable_mevm() as m:
+            # empty call target
+            empty = m.create_account(address=0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)
+            # nonempty call target
+            nonempty = m.create_account(address=0x1111111111111111111111111111111111111111, nonce=1)
+
+            asm_sd_empty =  """ PUSH20 0xffffffffffffffffffffffffffffffffffffffff
+                                SELFDESTRUCT
+                            """
+            asm_sd_nonempty =   """ PUSH20 0x1111111111111111111111111111111111111111
+                                    SELFDESTRUCT
+                                """
+
+            caller = m.create_account(
+                address=0x222222222222222222222222222222222222222, balance=1000000000000000000
+            )
+
+            # selfdestruct to empty acct with no value
+            sd_empty = m.create_account(code=EVMAsm.assemble(asm_sd_empty))
+            m.transaction(caller=caller, address=sd_empty, data=b"", value=0, gas=50000000)
+            self.assertEqual(m.count_ready_states(), 1)
+            state = next(m.ready_states)
+            txs = state.platform.transactions
+            # no value, so only static cost charged and refund is gas_used / 2
+            self.assertEqual(txs[-1].used_gas, round(GSDSTATIC - (GSDSTATIC / 2)))
+
+            # selfdestruct to existing acct with value > 0
+            sd_nonempty = m.create_account(code=EVMAsm.assemble(asm_sd_nonempty))
+            m.transaction(caller=caller, address=sd_nonempty, data=b"", value=1, gas=50000000)
+            self.assertEqual(m.count_ready_states(), 1)
+            state = next(m.ready_states)
+            txs = state.platform.transactions
+            # recipient exists, so only static cost charged and refund is gas_used / 2
+            self.assertEqual(txs[-1].used_gas, round(GSDSTATIC - (GSDSTATIC / 2)))
+
+            # selfdestruct to empty acct with value > 0, forcing addition to state trie
+            sd_empty = m.create_account(code=EVMAsm.assemble(asm_sd_empty))
+            m.transaction(caller=caller, address=sd_empty, data=b"", value=1, gas=50000000)
+            self.assertEqual(m.count_ready_states(), 1)
+            state = next(m.ready_states)
+            txs = state.platform.transactions
+            # new account gas charged and full refund returned
+            self.assertEqual(txs[-1].used_gas, GSDSTATIC + GNEWACCOUNT - RSELFDESTRUCT)
+
 
 class EthPluginTests(unittest.TestCase):
     def test_FilterFunctions_fallback_function_matching(self):